Enterprises today conduct a significant amount of business that involves the use and/or dissemination of proprietary and/or confidential business applications, information and data. Such proprietary and/or confidential business applications, information, and data has been generated and developed by the enterprise at a substantial cost in funding and resources, and, accordingly, represents an extremely valuable asset of the enterprise. Of paramount concern to such enterprises is maintaining the security and integrity of such proprietary and/or confidential business applications, information and data, particularly in those instances where such proprietary and/or confidential business applications, information and/or data must be used outside the confines of the enterprise. Generally such proprietary and/or confidential business applications, information and data is stored within the enterprise in electronic format in enterprise storage, a centralized repository that provides for common management and security, as well as data sharing functions, for stored proprietary and/or confidential business applications, information and data. Access to such proprietary and/or confidential business applications, information, and data is generally via an enterprise server using landline networks.
With the increasing complexity and pace of business transactions in the world today, it is of paramount importance that enterprises provide prompt and easy access to its proprietary and/or confidential business applications, information, and data while concomitantly maintaining the security and integrity of such proprietary and/or confidential business applications, information, and data. While internal access to such proprietary and/or confidential business applications, information, and data in enterprise storage is generally a relatively convenient, painless, and secure process, the same cannot be said for remote access to proprietary and/or confidential business applications, information, and data in enterprise storage.
Prior to even initiating a remote communication session to access enterprise storage via a landline network, one must have access to a computer system such as a desktop computer or a laptop, which are not always readily available. The computer system must include the necessary hardware to connect such computer system to a landline system.
Presuming these hardware requirements are met, it will be appreciated that remote communication sessions with enterprise storage via landline networks are not subject to a high degree of security. Enterprises generally do not employ encryption/decryption schemes to protect proprietary and/or confidential business applications, information, and data that is transmitted over landline networks due to the high investment and operating costs and inconvenience in establishing and employing such schemes. Instead, enterprises tend to rely on the inherent difficulties involved in intercepting unencrypted proprietary and/or confidential business applications, information, and data transmitted over landline networks. Thus, remote access to proprietary and/or confidential business applications, information, and data poses a real and substantial risk to the enterprise. The foregoing problems are aggravated when one considers remote wireless communications with enterprise storage.
The risk of interception of proprietary and/or confidential business applications, information, and data transmitted via wireless communications is considerably greater for wireless communications than for communications via landline networks. For example, the transmitting frequencies used by wireless communication networks are generally public domain information. The basic equipment needed to intercept wireless communications is readily available on the open market and is relatively easy to implement.
A need exists to provide an enterprise communications system that allows the enterprise securely implement, access, use, and manage enterprise-specific proprietary and/or confidential business applications, information, and data for remote transactions. Such an enterprise communication system should provide a high degree of security for proprietary and/or confidential business applications, information, and data communicated outside of the enterprise while concomitantly not require a significant expenditure of funds and resources by the enterprise to implement such security schemes. Such a system should be relatively easy to implement, and should facilitate the confident use of wireless communications to conduct enterprise business transactions.
Digital mobile communication networks that provide secure wireless communication channels for voice and data transmissions are becoming available to and used by a larger percentage of the general population for personal communications. For example, the Global System for Mobile Communication (GSM) network is far and away the largest existing secure digital mobile communications network in the world (in North America the GSM network is identified as the GMS 1900 or PCS 1900 network since the North American network operates at 1.9 GHz). Current estimates suggest that there are in the neighborhood of 700 million GSM network users worldwide. And, at a present growth rate of approximately 10 million new users per month, the GSM network (and its technical evolutions such as 3GPP, UMTS, and IMT-2000) is likely to remain the predominant secure digital mobile communications network into the future. Secure digital mobile communication networks such as the GSM network are operative to regularly authenticate network users during communication sessions to ensure that such users are authorized to use the network and to provide true point-to-point encryption for wireless communications.
The general architecture of a generic GSM network is illustrated in FIG. 1 and is representative of such digital mobile communication networks. The GSM network, which provides telephony, bearer services, e.g., transmission and reception of data, Group 3 facsimile, and supplementary services to GSM users, comprises three functional entities, whose functions and interfaces are defined by ETSI specifications: (1) mobile stations; (2) base station subsystem; and (3) the network subsystem.
Each mobile station consists of a customized wireless communication device (hereinafter the “GSM terminal”) and an installed SIM (Subscriber Identity Module) card wherein the interfaces between the GSM terminal and the SIM card are standardized. The GSM terminal is physically customized, i.e., configured, for installation of any SIM card. The GSM terminal is also structurally and functionally configured, e.g., includes a user interface (key pad, display screen) and menu structure for user inputs, to interact with the SIM card (in fact, the GSM terminal is inoperative without a SIM card installed therein). Each GSM terminal is uniquely identified by serial number, the IMEI (International Mobile Equipment Identity).
The SIM card is a specific instance of a smart card or security/trust token for secure wireless communication networks, i.e., in this instance for the GSM network. Other representative examples of smart cards for secure wireless communication networks include the Universal Identity Module (UIM), the Removable User Identity Module (R-UIM), and the UMTS Subscriber Identity Module (USIM). The SIM represents the subscription contract between a specific subscriber (network user) and the GSM network operator, i.e., providing the means for authenticating the subscriber for network access and identifying GSM network services to which the subscriber is entitled, i.e., the SIM card is the subscriber's identity in the context of the GSM network. The SIM card is portable to any GSM terminal, thereby providing the subscriber with an unprecedented degree of personal mobility.
The SIM card is in fact a small computer, containing a standardized operating system (JavaCard™ is implemented in the SIM card; Smart Card for Windows and Multos™ are other standardized operating systems for smart cards) and system files, RAM and flash memory (for storage of data and applications), a microprocessor, and typically a cryptographic co-processor. The GSM network operator controls the distribution and the stored content, e.g., data, applications, of the SIM card. Stored on SIM cards configured for GSM networks are subscription and security-related data, e.g., a subscriber number (International Mobile Subscriber Identity (IMSI)) that uniquely identifies the subscriber, a network operator-assigned subscriber-specific call number (MSISDN), i.e., the subscriber's ‘phone number’ in the GSM network, the subscriber key and cryptographic algorithms for authentication of the subscriber and encryption of subscriber communications (specified by the GSM network operator), and subscriber personal data, e.g., the subscriber's password or personal identity number (PIN) for accessing the SIM card, personal telephone directory, call charging information, a log of recently-dialed numbers, short text messages (for use with SMS (Short Message Service)), and a personalized subscriber services portfolio, i.e., applications.
Also embedded in the SIM card is a SIM Application Toolkit (STK). The STK provides the functional capability, inter alia, to allow the subscriber to access and use embedded applications via the user interface of the GSM terminal, and to modify the menu structure of the GSM terminal in conjunction with the use of such applications. The STK also allows the GSM network operator to download new data and/or applications to the SIM card to implement new services for the subscriber.
The SIM card includes built-in security functions that preclude electronic access to the content stored in the SIM card, e.g., the content cannot be extracted from the SIM card or reverse engineered. These security functions will also erase/delete SIM card content in response to physical tampering detected utilizing conventional technologies such as micro-probing, ultra-violet light examination, and voltage, temperature, and clock manipulation.
The base station subsystem functions as the interface between mobile stations and the network subsystem and consists one or more base station controllers, each base station controller managing several base transceiver stations. Each base station controller manages the control functions and physical links between its base stations and the network subsystem. Each base transceiver station provides the wireless communication interface, i.e., radio link, for mobile stations within its coverage area (cell).
The network subsystem manages the mobility operations such as registration, authentication, location updating, handovers, and call routing for the GSM network and its subscribers, e.g., by means of the HLR (Home Location Register), VLR (Visitor Location Register), AUC (Authentication Center), and EIR (Equipment Identity Register). The network subsystem also provides the interface between mobile stations and fixed landline networks. More specifically, in the network subsystem the MSC (Mobile Switching Center) functions as a network-switching node, routing GSM wireless communications traffic to/from fixed landline networks such as PSTN (Public Switched Telephone Networks), ISDN (Integrated Services Digital Networks), PSPDN (Packet Switched Public Data Networks), and/or CSPDN Circuit Switched Public Data Networks). It will be appreciated that wireless traffic routed over fixed landline networks is not in an encrypted format since most landline network terminals do not avail themselves of any encryption/decryption technology.